England's retention of the Ashes may have many fans struggling for interest. Although victory was never going to save Australia in the fourth Test, both teams are competitive enough to challenge for every individual win.

For the hosts, an undefeated run would amount to another excellent sporting achievement in a British summer of success. Although Andy Flower's squad will fall just shy of a whitewash, rendering the Aussies winless after five tests would be a major coup for English cricket.

Michael Clarke's Baggy Greens are already looking to the future. An improved showing in the third Test saw the visitors come close to securing their opening win, but as reported by Sam Sheringham of BBC Sport, bad light and rain stopped play to help ensure the hosts maintained their grip on the series.

With plenty of cricket still to be played with the Oval clash and return series in Australia, what has the fourth Test taught us? Which players are ready to step up in the future? Let's break it down.

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Australia Readying Winter Series Shuffle

Darren Lehmann has one eye on Australia's return series in November. The coach has been quick to look at an interesting selection of alternative bowlers since England retained the prize at Old Trafford, indicating places are up for grabs later this year.

Both Lehmann and Michael Clarke are working together to find the best equipped team. Australia have struggled to mix up their bowling options this series and have often been caught short due to a lack of variation. Lehmann knows this and is now sharpening the edges of a squad that still has potential.

Nathan Lyon and Jackson Bird are amongst those who have been given Ashes experience with this in mind. The former played excellently throughout the fourth Test, taking a combined total of seven wickets across two innings. The 25-year-old hasn't been overawed by an occasion and has reacted well to initially being dropped for Ashton Agar, who ran out of steam.

Bird bowled Alastair Cook and James Anderson at the Riverside Ground, giving the paceman a decent start to his series. Australia need competition for places in order to maximise their output and must use this opportunity to give their talent increased exposure at this somewhat meaningless point in the contest.

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Ryan Harris is Key to Beating England

England were in control during the second innings until Ryan Harris stepped up. He has performed brilliantly throughout the series and the 33-year-old's seven-wicket haul at Chester-le-Street is amongst the highlights.

As reported by Vic Marks of The Guardian, Harris worked a long shift to help his side back into the test:

Harris kept straining for Michael Clarke, his captain. He induced a loose shot from Alastair Cook, then bent his back one more time to dispatch Jonathan Trott. England's No.3 had been rocking on to his front foot and whipping the ball through mid-wicket like a West Indian No.3 of three decades ago. Not for the first time Trott was somehow provoking comparisons with Viv Richards.

Harris sensed what had to be done. Such advances down the pitch demand a response: the bouncer, a delivery used surprisingly sparingly against Trott. Harris propelled a beauty and Trott was taken on the glove. Advance no more.

Australia have been slow to react across the series, often letting England get comfortable before taking action. Even so, Harris has continued to deliver with intelligence and quality. He has followed his natural instinct and reacted accordingly. Most importantly, his delivery has been top quality when the Aussies needed it.

As tweeted by Jesse Hogan of The Age, Harris' fourth Test haul is the best slew of Australian wickets since 2008-09:

Australian legend and current Sky Sports commentator Shane Warne was narked by the behaviour of England's players after the home side retained the Ashes. As Warne noted in his Daily Telegraph column, the trophy holders shouldn't get ahead of themselves just yet:

Yes, England are a very good cricket team and it is their choice how they convey messages to the press and act on and off the field, and also how they want to represent themselves individually and collectively as a team. But to me there were a few moments at Old Trafford when I thought, "Hang on, who do you think you are?"

I saw an interview with Ian Ward after day two and he said it had been a tough couple of days for England, which it had been, but Graeme Swann replied, "No, not really. We will just go out and bat now on this flat Old Trafford wicket."

Matt Prior was also very smug in his comments, which leads me to think perhaps it is a conscious effort or direction from Andy Flower to be arrogant and dismissive of the opposition. Let me tell you this, if you lose respect for the game and the opposition, cricket has a funny way of biting you on the backside.

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England might have felt the faint nibble of teeth already. Australia were likely to win the third Test before rain and bad light stopped play. At 2-1, the series would have been far more tense for the expectant hosts.

It is worth considering what would have happened if the weather had held up for Clarke's men in the third Test. If the Aussies had enjoyed a little more luck, then this series might have been delicately poised. Although Australia lost momentum on Day 4 of the fourth Test, their confidence would have been galvanised going to Chester-le-Street had they taken the third Test.

When The Gabba's first ball arrives in Brisbane later this year, such a realisation puts the two teams closer together than many think.